A simple module system is provided, designed to capture the bare essentials of a collection of coherent code. The current module system is just associated with each library file for simplicity's sake. The methods provides: and requires: applied to the context will add to and check against a global features sequence respectively, and missing requirements are noted as the code is loaded. Again for simplicity, features currently contains and expects Symbols. The primitive fileIn method also invokes a hook to set the currentModule in its context.